Filamentary structure in chemical tracer distributions near the subtropical jet following a wave breaking event Atmospheric Chemistry and Physics DOI 10.5194/acp-13-10517-2013 31 October 2013 This paper presents a set of observations and analyses of trace gas cross sections in the extratropical upper troposphere/lower stratosphere (UTLS). Read more
Nitrous Oxide (N2O) production in axenic Chlorella vulgaris microalgae cultures: evidence, putative pathways, and potential environmental impacts Biogeosciences DOI 10.5194/bg-10-6737-2013 25 October 2013 Using antibiotic assays and genomic analysis, this study demonstrates nitrous oxide (N2O) is generated from axenic Chlorella vulgaris cultures. In batch assays, this production is magnified under conditions favouring intracellular nitrite accumulation, but repressed when nitrate reductase (NR) activity is inhibited. Read more
Global monitoring of terrestrial chlorophyll fluorescence from moderate-spectral-resolution near-infrared satellite measurements: methodology, simulations, and application to GOME-2 Atmospheric Measurement Techniques DOI 10.5194/amt-6-2803-2013 25 October 2013 Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data with a simplified radiative transfer model to disentangle the spectral signatures of three basic components: atmospheric absorption, surface reflectance, and fluorescence radiance. An empirically based principal component analysis approach is employed, primarily using cloudy data over ocean, to model and solve for the atmospheric absorption. Read more
Cloud-resolving simulations of mercury scavenging and deposition in thunderstorms Atmospheric Chemistry and Physics DOI 10.5194/acp-13-10143-2013 15 October 2013 This study examines dynamical and microphysical features of convective clouds that affect mercury (Hg) wet scavenging and concentrations in rainfall. Read more
Carbonate mineral saturation states in the East China Sea: present conditions and future scenarios Biogeosciences DOI 10.5194/bg-10-6453-2013 11 October 2013 To assess the impact of rising atmospheric CO2 and eutrophication on the carbonate chemistry of the East China Sea shelf waters, saturation states (Ω) for two important biologically relevant carbonate minerals were calculated throughout the water column. Read more
A novel salinity proxy based on Na incorporation into foraminiferal calcite Biogeosciences DOI 10.5194/bg-10-6375-2013 9 October 2013 This study investigates the impact of salinity on foraminiferal Na/Ca values by laser ablation ICP-MS analyses of specimens of the benthic foraminifer Ammonia tepida cultured at a range of salinities (30.0–38.6). Read more
Critical impacts of global warming on land ecosystems Earth System Dynamics DOI 10.5194/esd-4-347-2013 8 October 2013 Here we present a macro-scale analysis of climate change impacts on terrestrial ecosystems based on newly developed sets of climate scenarios featuring a step-wise sampling of global mean temperature increase between 1.5 and 5 K by 2100. Read more
Remote sensing of LAI, chlorophyll and leaf nitrogen pools of crop- and grasslands in five European landscapes Biogeosciences DOI 10.5194/bg-10-6279-2013 7 October 2013 The purpose of this study is to use field-based and satellite remote-sensing-based methods to assess leaf nitrogen pools in five diverse European agricultural landscapes located in Denmark, Scotland (United Kingdom), Poland, the Netherlands and Italy. Read more
Naphthalene SOA: redox activity and naphthoquinone gas–particle partitioning Atmospheric Chemistry and Physics DOI 10.5194/acp-13-9731-2013 2 October 2013 Chamber secondary organic aerosol from low-NOx photooxidation of naphthalene by hydroxyl radical was examined with respect to its redox cycling behaviour using the dithiothreitol assay. Read more
Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models Biogeosciences DOI 10.5194/bg-10-6225-2013 2 October 2013 Ocean ecosystems are increasingly stressed by human-induced changes of their physical, chemical and biological environment. Here, we use the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how stressors such as warming, acidification deoxygenation and changes in primary productivity by marine phytoplankton, may evolve over the course of the 21st century. Read more
Antarctic ice-mass balance 2003 to 2012: regional reanalysis of GRACE satellite gravimetry measurements with improved estimate of glacial-isostatic adjustment based on GPS uplift rates The Cryosphere DOI 10.5194/tc-7-1499-2013 25 September 2013 We present regional-scale mass balances for 25 drainage basins of the Antarctic Ice Sheet (AIS) from satellite observations of the Gravity and Climate Experiment (GRACE) for time period January 2003 to September 2012. Read more
The impact of nitrogen and phosphorous limitation on the estimated terrestrial carbon balance and warming of land use change over the last 156 yr Earth System Dynamics DOI 10.5194/esd-4-333-2013 16 September 2013 We examine the impact of land use and land cover change (LULCC) over the period from 1850 to 2005 using an Earth system model that incorporates nitrogen and phosphorous limitation on the terrestrial carbon cycle. Read more
Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras Annales Geophysicae DOI 10.5194/angeo-31-1543-2013 6 September 2013 A new stereoscopic measurement technique is developed to obtain an all-sky altitude map of aurora using two ground-based digital single-lens reflex (DSLR) cameras. Read more
Black carbon in the Arctic: the underestimated role of gas flaring and residential combustion emissions Atmospheric Chemistry and Physics DOI 10.5194/acp-13-8833-2013 5 September 2013 Chemistry transport models and climate chemistry models struggle to reproduce the Arctic Haze phenomenon, and this has recently prompted changes in aerosol removal schemes to remedy the modeling problems. In this paper, we show that shortcomings in current emission data sets are at least as important. Read more
The magnitude and causes of uncertainty in global model simulations of cloud condensation nuclei Atmospheric Chemistry and Physics DOI 10.5194/acp-13-8879-2013 5 September 2013 Here we perform a variance-based analysis of a global 3-D aerosol microphysics model to quantify the magnitude and leading causes of parametric uncertainty in model-estimated present-day concentrations of cloud condensation nuclei. Read more
Global CO2 fluxes estimated from GOSAT retrievals of total column CO2 Atmospheric Chemistry and Physics DOI 10.5194/acp-13-8695-2013 3 September 2013 This paper presents one of the first estimates of the global distribution of CO2surface fluxes using total column CO2 measurements retrieved by the SRON-KIT RemoTeC algorithm from the Greenhouse gases Observing SATellite (GOSAT). Read more
Gravitational separation in the stratosphere – a new indicator of atmospheric circulation Atmospheric Chemistry and Physics DOI 10.5194/acp-13-8787-2013 3 September 2013 The O2/N2 ratio observed in the middle stratosphere, corrected for gravitational separation, showed the same mean air age as estimated from the CO2 mole fraction. Therefore, gravitational separation is usable as a new indicator of changes in the atmospheric circulation in the stratosphere. Read more
North–south palaeohydrological contrasts in the central Mediterranean during the Holocene: tentative synthesis and working hypotheses Climate of the Past DOI 10.5194/cp-9-2043-2013 2 September 2013 On the basis of a multi-proxy approach and a strategy combining lacustrine and marine records along a north–south transect, data collected in the central Mediterranean within the framework of a collaborative project have led to reconstruction of high-resolution and well-dated palaeohydrological records and to assessment of their spatial and temporal coherency. Read more
Climate response to imposed solar radiation reductions in high latitudes Earth System Dynamics DOI 10.5194/esd-4-301-2013 2 September 2013 The results of this paper suggest that, until emissions reductions are sufficient to limit the warming influence of increasing greenhouse gas concentrations, polar reductions in solar radiation, if they could be efficiently and effectively implemented, warrant further research as an approach to moderating the early stages of both high-latitude and global warming. Read more
Consistent increase in Indian monsoon rainfall and its variability across CMIP-5 models Earth System Dynamics DOI 10.5194/esd-4-287-2013 28 August 2013 The possibility of an impact of global warming on the Indian monsoon is of critical importance for the large population of this region. Future projections within the Coupled Model Intercomparison Project Phase 3 (CMIP-3) showed a wide range of trends with varying magnitude and sign across models. Here the Indian summer monsoon rainfall is evaluated in 20 CMIP-5 models for the period 1850 to 2100. Read more